[brad s1]

Last year my AC compressor was making an awful whine noise, so I cut the belt out, noise gone... Now it's heating up outside so last night I threw a new belt on which was a project to say the least. Upon initial start the whine was very evident again, drove around a bit and it was HORRIBLE. I know other people have had this issue. The Rav CD tells you to bottom out the 13mm screw then tighten, which yields maximum tension on the belt. I backed the tensioner off a bit, maybe 1/8th" from maximum tension, belt is still snug... No more whine and the AC is ice cold `)

 

[ibis1]

From what you have described, I would say your whine is from the tensioner and not the A/C compressor. ibis1 :wink:

 

[linuxfreakus]

I agree, sounds like it could be the tensioner. If it is bad it could cause the belt to fail... in theory it could be bad depending on the trajectory of the belt upon shredding/flying off at high speed. On the other hand, if it sounds good now, maybe it was just slipping. I don't think the tensioner costs much though, so might be worth a precautionary replacement.

 

[linuxfreakus]

Amazingly, on my BMW, I once lost a whole pulley... it was just gone and I have no idea when it happened, noticed it when checking oil/coolant level one day. I was lucky I didn't lose the belt and cook my engine (somehow it was still tight, I guess the tensioner picked up the slack).

 

[brad s1]

From what you have described, I would say your whine is from the tensioner and not the A/C compressor. ibis1 :wink:

That's what I assumed too, but the tensioner is new last year, that was the first thing I swapped out to remedy this issue along with the new belt, but when the noise continued I just pulled the belt out. I didn't think to adjust tension. I noticed the belt seemed awfully tight with the tensioner in the maxed out position Friday, backing it off just a bit as I said the noise is gone.

There have been some ongoing threads here with owners reporting dealers replacing big money parts to remedy this, relieving a bit of the tension is worth a try IMO.

I agree, sounds like it could be the tensioner. If it is bad it could cause the belt to fail... in theory it could be bad depending on the trajectory of the belt upon shredding/flying off at high speed. On the other hand, if it sounds good now, maybe it was just slipping. I don't think the tensioner costs much though, so might be worth a precautionary replacement.

It isn't slipping. I had the range out all day yesterday, no belt dust anywhere. Usually when a belt slips you get a burning smell and belt dust in the general area... Not the case here. The belt is still very snug.

Regardless, the noise is gone and the problem is fixed.

 

[rfdiii]

Question:

Was the whine akin to a turbo whine, where the sound increases/decreases with engine speed? If so, I have a similar issue -- dealer changed out compressor at last visit and it was quiet for a bit, but now I'm hearing the compressor again.

I guess as a starting point, should one hear the compressor while driving around town?

Thanks.

 

[brad s1]

Question:

Was the whine akin to a turbo whine, where the sound increases/decreases with engine speed? If so, I have a similar issue -- dealer changed out compressor at last visit and it was quiet for a bit, but now I'm hearing the compressor again.

I guess as a starting point, should one hear the compressor while driving around town?

Thanks.

Yes, the sound increases in pitch and volume with RPM. No, you shouldn't hear a whine while driving at all. If you're up to it just back the tension down ever so slightly and I bet your noise vanishes... Obviously you want the belt snug still, back off too much could cause major issues.

good luck.